The present invention relates generally to an elevator system for high buildings and, in particular, to an apparatus for controlling the movement of a plurality of passenger carrying cars in and between a plurality of elevator shafts in a building.
There is a demand for a system of cable-free cars for the efficient transport of personnel in very high buildings. With such a system, it is possible to control the movement of several cars in the same shaft and thus increase the conveying capacity and correspondingly shorten the waiting times of the personnel. It is desirable in such systems that the cars move horizontally from one shaft into another at least at the lower and upper ends of the shafts. Such systems are shown in the prior art.
The German published patent specification 1 251 925 describes an elevator car which is guided and driven by rubber wheels running in the shaft corners. To reduce the required driving power, a counterweight is provided, which is likewise guided in rubber-tired wheels running in masonry grooves. The system is restricted to one car per shaft and no shaft change capability is provided.
The German published patent specification 2 154 923 describes a passenger elevator in which boarding and exiting places are provided beside tile travel shaft for different floors. A car can be pushed horizontally into these boarding and exiting places, for which co-moving guide rail pieces are replaced by additional pieces in order to close the gap in the guides and enable an overtaking of the stopping car by a moving car. The cars are individually powered and, in principle, more than one car can travel in the same shaft at the same time.
A similar system is described in the German published patent specification 1 912 520. However, a difference is that the cars are driven by a circulating cable.
A circulating transport device, in particular a loop-type elevator device, is described in the German published patent specification 2 232 739. Individually powered cars provided with linear drives can serve stopping places by changing over by way of resettable guide shunt switches from a traveling shaft into a stopping shaft. The system is constructed on the circulation principle with several cars in circulation at the same time.
An elevator system shown in the U.S. Pat. No. 3,658,155 includes several individually powered cars moving in two vertical shafts connected in a loop. The cars can move horizontally into boarding and exiting places in each shaft and change at the bottom and at the top from one shaft to another. A transverse shaft at the bottom of the vertical shafts provides a place for several cars to stop to load and unload passengers. The cars are driven by toothed wheels engaging a toothed rack in the shafts.
However, the above described systems do not provide a universal conveying system having the full freedom of movement of the individual cars everywhere along the travel path.